已知文法G(S)为:S→if S else S | if S | a

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已知文法G(S)为:S→if S else S | if S | a
证明该文法是二义的.

对于句子：if if a1 else a1 存在两种最左推导
一、s => if s else s => if if s else s => if if a1 else a2
二、s => if s => if if s else s => if if a1 else a2
故文法G(S):S→if S else S | if S | a
具有二义性.
证毕.

已知文法G(S)为:S→if S else S | if S | a if(s[i]>=‘a’&&s[i] 编译原理设有文法G（S） If It's Not n g s s s w a if you're trying to turn me into someone else,it's easy to s if(s[i]>='0'&&s[i] Let me see if there's ___left. A anything else B something e What if everyone else brings a present?为什么bring加s? 编译原理推导题对文法（G）=（Vn,Vr,P,S）,Vn={S,A,B} Vr={a,b}开始符为S,P . everyone's else or everyone else's? main() { int a,s,max; scanf("%d%d",&a,&s); if(a>s) { max=a }